Not too many details or specifics yet:

Blue Ring serves commercial and government customers and can support a variety of missions in medium Earth orbit out to the cislunar region and beyond. The platform provides end-to-end services that span hosting, transportation, refueling, data relay, and logistics, including an “in-space” cloud computing capability. Blue Ring can host payloads of more than 3,000 kg and provides unprecedented delta-V capabilities and mission flexibility.

It seems akin to RocketLab’s Photon satellite bus and kickstage, but for tonne-class payloads.